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NFS: Fix fcntl F_GETLK not reporting some conflicts
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / disk-io.c
blobc547cca26a266e962bbb760c0616e0846439d81d
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/crc32c.h>
30 #include <linux/slab.h>
31 #include <linux/migrate.h>
32 #include "compat.h"
33 #include "ctree.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "btrfs_inode.h"
37 #include "volumes.h"
38 #include "print-tree.h"
39 #include "async-thread.h"
40 #include "locking.h"
41 #include "tree-log.h"
42 #include "free-space-cache.h"
43
44 static struct extent_io_ops btree_extent_io_ops;
45 static void end_workqueue_fn(struct btrfs_work *work);
46 static void free_fs_root(struct btrfs_root *root);
47
48 /*
49 * end_io_wq structs are used to do processing in task context when an IO is
50 * complete. This is used during reads to verify checksums, and it is used
51 * by writes to insert metadata for new file extents after IO is complete.
52 */
53 struct end_io_wq {
54 struct bio *bio;
55 bio_end_io_t *end_io;
56 void *private;
57 struct btrfs_fs_info *info;
58 int error;
59 int metadata;
60 struct list_head list;
61 struct btrfs_work work;
62 };
63
64 /*
65 * async submit bios are used to offload expensive checksumming
66 * onto the worker threads. They checksum file and metadata bios
67 * just before they are sent down the IO stack.
68 */
69 struct async_submit_bio {
70 struct inode *inode;
71 struct bio *bio;
72 struct list_head list;
73 extent_submit_bio_hook_t *submit_bio_start;
74 extent_submit_bio_hook_t *submit_bio_done;
75 int rw;
76 int mirror_num;
77 unsigned long bio_flags;
78 /*
79 * bio_offset is optional, can be used if the pages in the bio
80 * can't tell us where in the file the bio should go
81 */
82 u64 bio_offset;
83 struct btrfs_work work;
84 };
85
86 /* These are used to set the lockdep class on the extent buffer locks.
87 * The class is set by the readpage_end_io_hook after the buffer has
88 * passed csum validation but before the pages are unlocked.
89 *
90 * The lockdep class is also set by btrfs_init_new_buffer on freshly
91 * allocated blocks.
92 *
93 * The class is based on the level in the tree block, which allows lockdep
94 * to know that lower nodes nest inside the locks of higher nodes.
95 *
96 * We also add a check to make sure the highest level of the tree is
97 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
98 * code needs update as well.
99 */
100 #ifdef CONFIG_DEBUG_LOCK_ALLOC
101 # if BTRFS_MAX_LEVEL != 8
102 # error
103 # endif
104 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
105 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
106 /* leaf */
107 "btrfs-extent-00",
108 "btrfs-extent-01",
109 "btrfs-extent-02",
110 "btrfs-extent-03",
111 "btrfs-extent-04",
112 "btrfs-extent-05",
113 "btrfs-extent-06",
114 "btrfs-extent-07",
115 /* highest possible level */
116 "btrfs-extent-08",
117 };
118 #endif
119
120 /*
121 * extents on the btree inode are pretty simple, there's one extent
122 * that covers the entire device
123 */
124 static struct extent_map *btree_get_extent(struct inode *inode,
125 struct page *page, size_t page_offset, u64 start, u64 len,
126 int create)
127 {
128 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
129 struct extent_map *em;
130 int ret;
131
132 read_lock(&em_tree->lock);
133 em = lookup_extent_mapping(em_tree, start, len);
134 if (em) {
135 em->bdev =
136 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
137 read_unlock(&em_tree->lock);
138 goto out;
139 }
140 read_unlock(&em_tree->lock);
141
142 em = alloc_extent_map(GFP_NOFS);
143 if (!em) {
144 em = ERR_PTR(-ENOMEM);
145 goto out;
146 }
147 em->start = 0;
148 em->len = (u64)-1;
149 em->block_len = (u64)-1;
150 em->block_start = 0;
151 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
152
153 write_lock(&em_tree->lock);
154 ret = add_extent_mapping(em_tree, em);
155 if (ret == -EEXIST) {
156 u64 failed_start = em->start;
157 u64 failed_len = em->len;
158
159 free_extent_map(em);
160 em = lookup_extent_mapping(em_tree, start, len);
161 if (em) {
162 ret = 0;
163 } else {
164 em = lookup_extent_mapping(em_tree, failed_start,
165 failed_len);
166 ret = -EIO;
167 }
168 } else if (ret) {
169 free_extent_map(em);
170 em = NULL;
171 }
172 write_unlock(&em_tree->lock);
173
174 if (ret)
175 em = ERR_PTR(ret);
176 out:
177 return em;
178 }
179
180 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
181 {
182 return crc32c(seed, data, len);
183 }
184
185 void btrfs_csum_final(u32 crc, char *result)
186 {
187 *(__le32 *)result = ~cpu_to_le32(crc);
188 }
189
190 /*
191 * compute the csum for a btree block, and either verify it or write it
192 * into the csum field of the block.
193 */
194 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
195 int verify)
196 {
197 u16 csum_size =
198 btrfs_super_csum_size(&root->fs_info->super_copy);
199 char *result = NULL;
200 unsigned long len;
201 unsigned long cur_len;
202 unsigned long offset = BTRFS_CSUM_SIZE;
203 char *map_token = NULL;
204 char *kaddr;
205 unsigned long map_start;
206 unsigned long map_len;
207 int err;
208 u32 crc = ~(u32)0;
209 unsigned long inline_result;
210
211 len = buf->len - offset;
212 while (len > 0) {
213 err = map_private_extent_buffer(buf, offset, 32,
214 &map_token, &kaddr,
215 &map_start, &map_len, KM_USER0);
216 if (err)
217 return 1;
218 cur_len = min(len, map_len - (offset - map_start));
219 crc = btrfs_csum_data(root, kaddr + offset - map_start,
220 crc, cur_len);
221 len -= cur_len;
222 offset += cur_len;
223 unmap_extent_buffer(buf, map_token, KM_USER0);
224 }
225 if (csum_size > sizeof(inline_result)) {
226 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
227 if (!result)
228 return 1;
229 } else {
230 result = (char *)&inline_result;
231 }
232
233 btrfs_csum_final(crc, result);
234
235 if (verify) {
236 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
237 u32 val;
238 u32 found = 0;
239 memcpy(&found, result, csum_size);
240
241 read_extent_buffer(buf, &val, 0, csum_size);
242 if (printk_ratelimit()) {
243 printk(KERN_INFO "btrfs: %s checksum verify "
244 "failed on %llu wanted %X found %X "
245 "level %d\n",
246 root->fs_info->sb->s_id,
247 (unsigned long long)buf->start, val, found,
248 btrfs_header_level(buf));
249 }
250 if (result != (char *)&inline_result)
251 kfree(result);
252 return 1;
253 }
254 } else {
255 write_extent_buffer(buf, result, 0, csum_size);
256 }
257 if (result != (char *)&inline_result)
258 kfree(result);
259 return 0;
260 }
261
262 /*
263 * we can't consider a given block up to date unless the transid of the
264 * block matches the transid in the parent node's pointer. This is how we
265 * detect blocks that either didn't get written at all or got written
266 * in the wrong place.
267 */
268 static int verify_parent_transid(struct extent_io_tree *io_tree,
269 struct extent_buffer *eb, u64 parent_transid)
270 {
271 struct extent_state *cached_state = NULL;
272 int ret;
273
274 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
275 return 0;
276
277 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
278 0, &cached_state, GFP_NOFS);
279 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
280 btrfs_header_generation(eb) == parent_transid) {
281 ret = 0;
282 goto out;
283 }
284 if (printk_ratelimit()) {
285 printk("parent transid verify failed on %llu wanted %llu "
286 "found %llu\n",
287 (unsigned long long)eb->start,
288 (unsigned long long)parent_transid,
289 (unsigned long long)btrfs_header_generation(eb));
290 }
291 ret = 1;
292 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
293 out:
294 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
295 &cached_state, GFP_NOFS);
296 return ret;
297 }
298
299 /*
300 * helper to read a given tree block, doing retries as required when
301 * the checksums don't match and we have alternate mirrors to try.
302 */
303 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
304 struct extent_buffer *eb,
305 u64 start, u64 parent_transid)
306 {
307 struct extent_io_tree *io_tree;
308 int ret;
309 int num_copies = 0;
310 int mirror_num = 0;
311
312 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
313 while (1) {
314 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
315 btree_get_extent, mirror_num);
316 if (!ret &&
317 !verify_parent_transid(io_tree, eb, parent_transid))
318 return ret;
319
320 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
321 eb->start, eb->len);
322 if (num_copies == 1)
323 return ret;
324
325 mirror_num++;
326 if (mirror_num > num_copies)
327 return ret;
328 }
329 return -EIO;
330 }
331
332 /*
333 * checksum a dirty tree block before IO. This has extra checks to make sure
334 * we only fill in the checksum field in the first page of a multi-page block
335 */
336
337 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
338 {
339 struct extent_io_tree *tree;
340 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
341 u64 found_start;
342 unsigned long len;
343 struct extent_buffer *eb;
344 int ret;
345
346 tree = &BTRFS_I(page->mapping->host)->io_tree;
347
348 if (page->private == EXTENT_PAGE_PRIVATE)
349 goto out;
350 if (!page->private)
351 goto out;
352 len = page->private >> 2;
353 WARN_ON(len == 0);
354
355 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
356 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
357 btrfs_header_generation(eb));
358 BUG_ON(ret);
359 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
360
361 found_start = btrfs_header_bytenr(eb);
362 if (found_start != start) {
363 WARN_ON(1);
364 goto err;
365 }
366 if (eb->first_page != page) {
367 WARN_ON(1);
368 goto err;
369 }
370 if (!PageUptodate(page)) {
371 WARN_ON(1);
372 goto err;
373 }
374 csum_tree_block(root, eb, 0);
375 err:
376 free_extent_buffer(eb);
377 out:
378 return 0;
379 }
380
381 static int check_tree_block_fsid(struct btrfs_root *root,
382 struct extent_buffer *eb)
383 {
384 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
385 u8 fsid[BTRFS_UUID_SIZE];
386 int ret = 1;
387
388 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
389 BTRFS_FSID_SIZE);
390 while (fs_devices) {
391 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
392 ret = 0;
393 break;
394 }
395 fs_devices = fs_devices->seed;
396 }
397 return ret;
398 }
399
400 #ifdef CONFIG_DEBUG_LOCK_ALLOC
401 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
402 {
403 lockdep_set_class_and_name(&eb->lock,
404 &btrfs_eb_class[level],
405 btrfs_eb_name[level]);
406 }
407 #endif
408
409 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
410 struct extent_state *state)
411 {
412 struct extent_io_tree *tree;
413 u64 found_start;
414 int found_level;
415 unsigned long len;
416 struct extent_buffer *eb;
417 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
418 int ret = 0;
419
420 tree = &BTRFS_I(page->mapping->host)->io_tree;
421 if (page->private == EXTENT_PAGE_PRIVATE)
422 goto out;
423 if (!page->private)
424 goto out;
425
426 len = page->private >> 2;
427 WARN_ON(len == 0);
428
429 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
430
431 found_start = btrfs_header_bytenr(eb);
432 if (found_start != start) {
433 if (printk_ratelimit()) {
434 printk(KERN_INFO "btrfs bad tree block start "
435 "%llu %llu\n",
436 (unsigned long long)found_start,
437 (unsigned long long)eb->start);
438 }
439 ret = -EIO;
440 goto err;
441 }
442 if (eb->first_page != page) {
443 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
444 eb->first_page->index, page->index);
445 WARN_ON(1);
446 ret = -EIO;
447 goto err;
448 }
449 if (check_tree_block_fsid(root, eb)) {
450 if (printk_ratelimit()) {
451 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
452 (unsigned long long)eb->start);
453 }
454 ret = -EIO;
455 goto err;
456 }
457 found_level = btrfs_header_level(eb);
458
459 btrfs_set_buffer_lockdep_class(eb, found_level);
460
461 ret = csum_tree_block(root, eb, 1);
462 if (ret)
463 ret = -EIO;
464
465 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
466 end = eb->start + end - 1;
467 err:
468 free_extent_buffer(eb);
469 out:
470 return ret;
471 }
472
473 static void end_workqueue_bio(struct bio *bio, int err)
474 {
475 struct end_io_wq *end_io_wq = bio->bi_private;
476 struct btrfs_fs_info *fs_info;
477
478 fs_info = end_io_wq->info;
479 end_io_wq->error = err;
480 end_io_wq->work.func = end_workqueue_fn;
481 end_io_wq->work.flags = 0;
482
483 if (bio->bi_rw & REQ_WRITE) {
484 if (end_io_wq->metadata == 1)
485 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
486 &end_io_wq->work);
487 else if (end_io_wq->metadata == 2)
488 btrfs_queue_worker(&fs_info->endio_freespace_worker,
489 &end_io_wq->work);
490 else
491 btrfs_queue_worker(&fs_info->endio_write_workers,
492 &end_io_wq->work);
493 } else {
494 if (end_io_wq->metadata)
495 btrfs_queue_worker(&fs_info->endio_meta_workers,
496 &end_io_wq->work);
497 else
498 btrfs_queue_worker(&fs_info->endio_workers,
499 &end_io_wq->work);
500 }
501 }
502
503 /*
504 * For the metadata arg you want
505 *
506 * 0 - if data
507 * 1 - if normal metadta
508 * 2 - if writing to the free space cache area
509 */
510 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
511 int metadata)
512 {
513 struct end_io_wq *end_io_wq;
514 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
515 if (!end_io_wq)
516 return -ENOMEM;
517
518 end_io_wq->private = bio->bi_private;
519 end_io_wq->end_io = bio->bi_end_io;
520 end_io_wq->info = info;
521 end_io_wq->error = 0;
522 end_io_wq->bio = bio;
523 end_io_wq->metadata = metadata;
524
525 bio->bi_private = end_io_wq;
526 bio->bi_end_io = end_workqueue_bio;
527 return 0;
528 }
529
530 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
531 {
532 unsigned long limit = min_t(unsigned long,
533 info->workers.max_workers,
534 info->fs_devices->open_devices);
535 return 256 * limit;
536 }
537
538 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
539 {
540 return atomic_read(&info->nr_async_bios) >
541 btrfs_async_submit_limit(info);
542 }
543
544 static void run_one_async_start(struct btrfs_work *work)
545 {
546 struct async_submit_bio *async;
547
548 async = container_of(work, struct async_submit_bio, work);
549 async->submit_bio_start(async->inode, async->rw, async->bio,
550 async->mirror_num, async->bio_flags,
551 async->bio_offset);
552 }
553
554 static void run_one_async_done(struct btrfs_work *work)
555 {
556 struct btrfs_fs_info *fs_info;
557 struct async_submit_bio *async;
558 int limit;
559
560 async = container_of(work, struct async_submit_bio, work);
561 fs_info = BTRFS_I(async->inode)->root->fs_info;
562
563 limit = btrfs_async_submit_limit(fs_info);
564 limit = limit * 2 / 3;
565
566 atomic_dec(&fs_info->nr_async_submits);
567
568 if (atomic_read(&fs_info->nr_async_submits) < limit &&
569 waitqueue_active(&fs_info->async_submit_wait))
570 wake_up(&fs_info->async_submit_wait);
571
572 async->submit_bio_done(async->inode, async->rw, async->bio,
573 async->mirror_num, async->bio_flags,
574 async->bio_offset);
575 }
576
577 static void run_one_async_free(struct btrfs_work *work)
578 {
579 struct async_submit_bio *async;
580
581 async = container_of(work, struct async_submit_bio, work);
582 kfree(async);
583 }
584
585 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
586 int rw, struct bio *bio, int mirror_num,
587 unsigned long bio_flags,
588 u64 bio_offset,
589 extent_submit_bio_hook_t *submit_bio_start,
590 extent_submit_bio_hook_t *submit_bio_done)
591 {
592 struct async_submit_bio *async;
593
594 async = kmalloc(sizeof(*async), GFP_NOFS);
595 if (!async)
596 return -ENOMEM;
597
598 async->inode = inode;
599 async->rw = rw;
600 async->bio = bio;
601 async->mirror_num = mirror_num;
602 async->submit_bio_start = submit_bio_start;
603 async->submit_bio_done = submit_bio_done;
604
605 async->work.func = run_one_async_start;
606 async->work.ordered_func = run_one_async_done;
607 async->work.ordered_free = run_one_async_free;
608
609 async->work.flags = 0;
610 async->bio_flags = bio_flags;
611 async->bio_offset = bio_offset;
612
613 atomic_inc(&fs_info->nr_async_submits);
614
615 if (rw & REQ_SYNC)
616 btrfs_set_work_high_prio(&async->work);
617
618 btrfs_queue_worker(&fs_info->workers, &async->work);
619
620 while (atomic_read(&fs_info->async_submit_draining) &&
621 atomic_read(&fs_info->nr_async_submits)) {
622 wait_event(fs_info->async_submit_wait,
623 (atomic_read(&fs_info->nr_async_submits) == 0));
624 }
625
626 return 0;
627 }
628
629 static int btree_csum_one_bio(struct bio *bio)
630 {
631 struct bio_vec *bvec = bio->bi_io_vec;
632 int bio_index = 0;
633 struct btrfs_root *root;
634
635 WARN_ON(bio->bi_vcnt <= 0);
636 while (bio_index < bio->bi_vcnt) {
637 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
638 csum_dirty_buffer(root, bvec->bv_page);
639 bio_index++;
640 bvec++;
641 }
642 return 0;
643 }
644
645 static int __btree_submit_bio_start(struct inode *inode, int rw,
646 struct bio *bio, int mirror_num,
647 unsigned long bio_flags,
648 u64 bio_offset)
649 {
650 /*
651 * when we're called for a write, we're already in the async
652 * submission context. Just jump into btrfs_map_bio
653 */
654 btree_csum_one_bio(bio);
655 return 0;
656 }
657
658 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
659 int mirror_num, unsigned long bio_flags,
660 u64 bio_offset)
661 {
662 /*
663 * when we're called for a write, we're already in the async
664 * submission context. Just jump into btrfs_map_bio
665 */
666 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
667 }
668
669 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
670 int mirror_num, unsigned long bio_flags,
671 u64 bio_offset)
672 {
673 int ret;
674
675 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
676 bio, 1);
677 BUG_ON(ret);
678
679 if (!(rw & REQ_WRITE)) {
680 /*
681 * called for a read, do the setup so that checksum validation
682 * can happen in the async kernel threads
683 */
684 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
685 mirror_num, 0);
686 }
687
688 /*
689 * kthread helpers are used to submit writes so that checksumming
690 * can happen in parallel across all CPUs
691 */
692 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
693 inode, rw, bio, mirror_num, 0,
694 bio_offset,
695 __btree_submit_bio_start,
696 __btree_submit_bio_done);
697 }
698
699 static int btree_migratepage(struct address_space *mapping,
700 struct page *newpage, struct page *page)
701 {
702 /*
703 * we can't safely write a btree page from here,
704 * we haven't done the locking hook
705 */
706 if (PageDirty(page))
707 return -EAGAIN;
708 /*
709 * Buffers may be managed in a filesystem specific way.
710 * We must have no buffers or drop them.
711 */
712 if (page_has_private(page) &&
713 !try_to_release_page(page, GFP_KERNEL))
714 return -EAGAIN;
715 #ifdef CONFIG_MIGRATION
716 return migrate_page(mapping, newpage, page);
717 #else
718 return -ENOSYS;
719 #endif
720 }
721
722 static int btree_writepage(struct page *page, struct writeback_control *wbc)
723 {
724 struct extent_io_tree *tree;
725 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
726 struct extent_buffer *eb;
727 int was_dirty;
728
729 tree = &BTRFS_I(page->mapping->host)->io_tree;
730 if (!(current->flags & PF_MEMALLOC)) {
731 return extent_write_full_page(tree, page,
732 btree_get_extent, wbc);
733 }
734
735 redirty_page_for_writepage(wbc, page);
736 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
737 WARN_ON(!eb);
738
739 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
740 if (!was_dirty) {
741 spin_lock(&root->fs_info->delalloc_lock);
742 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
743 spin_unlock(&root->fs_info->delalloc_lock);
744 }
745 free_extent_buffer(eb);
746
747 unlock_page(page);
748 return 0;
749 }
750
751 static int btree_writepages(struct address_space *mapping,
752 struct writeback_control *wbc)
753 {
754 struct extent_io_tree *tree;
755 tree = &BTRFS_I(mapping->host)->io_tree;
756 if (wbc->sync_mode == WB_SYNC_NONE) {
757 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
758 u64 num_dirty;
759 unsigned long thresh = 32 * 1024 * 1024;
760
761 if (wbc->for_kupdate)
762 return 0;
763
764 /* this is a bit racy, but that's ok */
765 num_dirty = root->fs_info->dirty_metadata_bytes;
766 if (num_dirty < thresh)
767 return 0;
768 }
769 return extent_writepages(tree, mapping, btree_get_extent, wbc);
770 }
771
772 static int btree_readpage(struct file *file, struct page *page)
773 {
774 struct extent_io_tree *tree;
775 tree = &BTRFS_I(page->mapping->host)->io_tree;
776 return extent_read_full_page(tree, page, btree_get_extent);
777 }
778
779 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
780 {
781 struct extent_io_tree *tree;
782 struct extent_map_tree *map;
783 int ret;
784
785 if (PageWriteback(page) || PageDirty(page))
786 return 0;
787
788 tree = &BTRFS_I(page->mapping->host)->io_tree;
789 map = &BTRFS_I(page->mapping->host)->extent_tree;
790
791 ret = try_release_extent_state(map, tree, page, gfp_flags);
792 if (!ret)
793 return 0;
794
795 ret = try_release_extent_buffer(tree, page);
796 if (ret == 1) {
797 ClearPagePrivate(page);
798 set_page_private(page, 0);
799 page_cache_release(page);
800 }
801
802 return ret;
803 }
804
805 static void btree_invalidatepage(struct page *page, unsigned long offset)
806 {
807 struct extent_io_tree *tree;
808 tree = &BTRFS_I(page->mapping->host)->io_tree;
809 extent_invalidatepage(tree, page, offset);
810 btree_releasepage(page, GFP_NOFS);
811 if (PagePrivate(page)) {
812 printk(KERN_WARNING "btrfs warning page private not zero "
813 "on page %llu\n", (unsigned long long)page_offset(page));
814 ClearPagePrivate(page);
815 set_page_private(page, 0);
816 page_cache_release(page);
817 }
818 }
819
820 static const struct address_space_operations btree_aops = {
821 .readpage = btree_readpage,
822 .writepage = btree_writepage,
823 .writepages = btree_writepages,
824 .releasepage = btree_releasepage,
825 .invalidatepage = btree_invalidatepage,
826 .sync_page = block_sync_page,
827 #ifdef CONFIG_MIGRATION
828 .migratepage = btree_migratepage,
829 #endif
830 };
831
832 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
833 u64 parent_transid)
834 {
835 struct extent_buffer *buf = NULL;
836 struct inode *btree_inode = root->fs_info->btree_inode;
837 int ret = 0;
838
839 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
840 if (!buf)
841 return 0;
842 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
843 buf, 0, 0, btree_get_extent, 0);
844 free_extent_buffer(buf);
845 return ret;
846 }
847
848 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
849 u64 bytenr, u32 blocksize)
850 {
851 struct inode *btree_inode = root->fs_info->btree_inode;
852 struct extent_buffer *eb;
853 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
854 bytenr, blocksize, GFP_NOFS);
855 return eb;
856 }
857
858 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
859 u64 bytenr, u32 blocksize)
860 {
861 struct inode *btree_inode = root->fs_info->btree_inode;
862 struct extent_buffer *eb;
863
864 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
865 bytenr, blocksize, NULL, GFP_NOFS);
866 return eb;
867 }
868
869
870 int btrfs_write_tree_block(struct extent_buffer *buf)
871 {
872 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
873 buf->start + buf->len - 1);
874 }
875
876 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
877 {
878 return filemap_fdatawait_range(buf->first_page->mapping,
879 buf->start, buf->start + buf->len - 1);
880 }
881
882 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
883 u32 blocksize, u64 parent_transid)
884 {
885 struct extent_buffer *buf = NULL;
886 int ret;
887
888 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
889 if (!buf)
890 return NULL;
891
892 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
893
894 if (ret == 0)
895 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
896 return buf;
897
898 }
899
900 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
901 struct extent_buffer *buf)
902 {
903 struct inode *btree_inode = root->fs_info->btree_inode;
904 if (btrfs_header_generation(buf) ==
905 root->fs_info->running_transaction->transid) {
906 btrfs_assert_tree_locked(buf);
907
908 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
909 spin_lock(&root->fs_info->delalloc_lock);
910 if (root->fs_info->dirty_metadata_bytes >= buf->len)
911 root->fs_info->dirty_metadata_bytes -= buf->len;
912 else
913 WARN_ON(1);
914 spin_unlock(&root->fs_info->delalloc_lock);
915 }
916
917 /* ugh, clear_extent_buffer_dirty needs to lock the page */
918 btrfs_set_lock_blocking(buf);
919 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
920 buf);
921 }
922 return 0;
923 }
924
925 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
926 u32 stripesize, struct btrfs_root *root,
927 struct btrfs_fs_info *fs_info,
928 u64 objectid)
929 {
930 root->node = NULL;
931 root->commit_root = NULL;
932 root->sectorsize = sectorsize;
933 root->nodesize = nodesize;
934 root->leafsize = leafsize;
935 root->stripesize = stripesize;
936 root->ref_cows = 0;
937 root->track_dirty = 0;
938 root->in_radix = 0;
939 root->orphan_item_inserted = 0;
940 root->orphan_cleanup_state = 0;
941
942 root->fs_info = fs_info;
943 root->objectid = objectid;
944 root->last_trans = 0;
945 root->highest_objectid = 0;
946 root->name = NULL;
947 root->in_sysfs = 0;
948 root->inode_tree = RB_ROOT;
949 root->block_rsv = NULL;
950 root->orphan_block_rsv = NULL;
951
952 INIT_LIST_HEAD(&root->dirty_list);
953 INIT_LIST_HEAD(&root->orphan_list);
954 INIT_LIST_HEAD(&root->root_list);
955 spin_lock_init(&root->node_lock);
956 spin_lock_init(&root->orphan_lock);
957 spin_lock_init(&root->inode_lock);
958 spin_lock_init(&root->accounting_lock);
959 mutex_init(&root->objectid_mutex);
960 mutex_init(&root->log_mutex);
961 init_waitqueue_head(&root->log_writer_wait);
962 init_waitqueue_head(&root->log_commit_wait[0]);
963 init_waitqueue_head(&root->log_commit_wait[1]);
964 atomic_set(&root->log_commit[0], 0);
965 atomic_set(&root->log_commit[1], 0);
966 atomic_set(&root->log_writers, 0);
967 root->log_batch = 0;
968 root->log_transid = 0;
969 root->last_log_commit = 0;
970 extent_io_tree_init(&root->dirty_log_pages,
971 fs_info->btree_inode->i_mapping, GFP_NOFS);
972
973 memset(&root->root_key, 0, sizeof(root->root_key));
974 memset(&root->root_item, 0, sizeof(root->root_item));
975 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
976 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
977 root->defrag_trans_start = fs_info->generation;
978 init_completion(&root->kobj_unregister);
979 root->defrag_running = 0;
980 root->root_key.objectid = objectid;
981 root->anon_super.s_root = NULL;
982 root->anon_super.s_dev = 0;
983 INIT_LIST_HEAD(&root->anon_super.s_list);
984 INIT_LIST_HEAD(&root->anon_super.s_instances);
985 init_rwsem(&root->anon_super.s_umount);
986
987 return 0;
988 }
989
990 static int find_and_setup_root(struct btrfs_root *tree_root,
991 struct btrfs_fs_info *fs_info,
992 u64 objectid,
993 struct btrfs_root *root)
994 {
995 int ret;
996 u32 blocksize;
997 u64 generation;
998
999 __setup_root(tree_root->nodesize, tree_root->leafsize,
1000 tree_root->sectorsize, tree_root->stripesize,
1001 root, fs_info, objectid);
1002 ret = btrfs_find_last_root(tree_root, objectid,
1003 &root->root_item, &root->root_key);
1004 if (ret > 0)
1005 return -ENOENT;
1006 BUG_ON(ret);
1007
1008 generation = btrfs_root_generation(&root->root_item);
1009 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1010 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1011 blocksize, generation);
1012 BUG_ON(!root->node);
1013 root->commit_root = btrfs_root_node(root);
1014 return 0;
1015 }
1016
1017 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1018 struct btrfs_fs_info *fs_info)
1019 {
1020 struct btrfs_root *root;
1021 struct btrfs_root *tree_root = fs_info->tree_root;
1022 struct extent_buffer *leaf;
1023
1024 root = kzalloc(sizeof(*root), GFP_NOFS);
1025 if (!root)
1026 return ERR_PTR(-ENOMEM);
1027
1028 __setup_root(tree_root->nodesize, tree_root->leafsize,
1029 tree_root->sectorsize, tree_root->stripesize,
1030 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1031
1032 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1033 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1034 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1035 /*
1036 * log trees do not get reference counted because they go away
1037 * before a real commit is actually done. They do store pointers
1038 * to file data extents, and those reference counts still get
1039 * updated (along with back refs to the log tree).
1040 */
1041 root->ref_cows = 0;
1042
1043 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1044 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1045 if (IS_ERR(leaf)) {
1046 kfree(root);
1047 return ERR_CAST(leaf);
1048 }
1049
1050 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1051 btrfs_set_header_bytenr(leaf, leaf->start);
1052 btrfs_set_header_generation(leaf, trans->transid);
1053 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1054 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1055 root->node = leaf;
1056
1057 write_extent_buffer(root->node, root->fs_info->fsid,
1058 (unsigned long)btrfs_header_fsid(root->node),
1059 BTRFS_FSID_SIZE);
1060 btrfs_mark_buffer_dirty(root->node);
1061 btrfs_tree_unlock(root->node);
1062 return root;
1063 }
1064
1065 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1066 struct btrfs_fs_info *fs_info)
1067 {
1068 struct btrfs_root *log_root;
1069
1070 log_root = alloc_log_tree(trans, fs_info);
1071 if (IS_ERR(log_root))
1072 return PTR_ERR(log_root);
1073 WARN_ON(fs_info->log_root_tree);
1074 fs_info->log_root_tree = log_root;
1075 return 0;
1076 }
1077
1078 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1079 struct btrfs_root *root)
1080 {
1081 struct btrfs_root *log_root;
1082 struct btrfs_inode_item *inode_item;
1083
1084 log_root = alloc_log_tree(trans, root->fs_info);
1085 if (IS_ERR(log_root))
1086 return PTR_ERR(log_root);
1087
1088 log_root->last_trans = trans->transid;
1089 log_root->root_key.offset = root->root_key.objectid;
1090
1091 inode_item = &log_root->root_item.inode;
1092 inode_item->generation = cpu_to_le64(1);
1093 inode_item->size = cpu_to_le64(3);
1094 inode_item->nlink = cpu_to_le32(1);
1095 inode_item->nbytes = cpu_to_le64(root->leafsize);
1096 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1097
1098 btrfs_set_root_node(&log_root->root_item, log_root->node);
1099
1100 WARN_ON(root->log_root);
1101 root->log_root = log_root;
1102 root->log_transid = 0;
1103 root->last_log_commit = 0;
1104 return 0;
1105 }
1106
1107 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1108 struct btrfs_key *location)
1109 {
1110 struct btrfs_root *root;
1111 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1112 struct btrfs_path *path;
1113 struct extent_buffer *l;
1114 u64 generation;
1115 u32 blocksize;
1116 int ret = 0;
1117
1118 root = kzalloc(sizeof(*root), GFP_NOFS);
1119 if (!root)
1120 return ERR_PTR(-ENOMEM);
1121 if (location->offset == (u64)-1) {
1122 ret = find_and_setup_root(tree_root, fs_info,
1123 location->objectid, root);
1124 if (ret) {
1125 kfree(root);
1126 return ERR_PTR(ret);
1127 }
1128 goto out;
1129 }
1130
1131 __setup_root(tree_root->nodesize, tree_root->leafsize,
1132 tree_root->sectorsize, tree_root->stripesize,
1133 root, fs_info, location->objectid);
1134
1135 path = btrfs_alloc_path();
1136 BUG_ON(!path);
1137 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1138 if (ret == 0) {
1139 l = path->nodes[0];
1140 read_extent_buffer(l, &root->root_item,
1141 btrfs_item_ptr_offset(l, path->slots[0]),
1142 sizeof(root->root_item));
1143 memcpy(&root->root_key, location, sizeof(*location));
1144 }
1145 btrfs_free_path(path);
1146 if (ret) {
1147 if (ret > 0)
1148 ret = -ENOENT;
1149 return ERR_PTR(ret);
1150 }
1151
1152 generation = btrfs_root_generation(&root->root_item);
1153 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1154 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1155 blocksize, generation);
1156 root->commit_root = btrfs_root_node(root);
1157 BUG_ON(!root->node);
1158 out:
1159 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1160 root->ref_cows = 1;
1161
1162 return root;
1163 }
1164
1165 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1166 u64 root_objectid)
1167 {
1168 struct btrfs_root *root;
1169
1170 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1171 return fs_info->tree_root;
1172 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1173 return fs_info->extent_root;
1174
1175 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1176 (unsigned long)root_objectid);
1177 return root;
1178 }
1179
1180 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1181 struct btrfs_key *location)
1182 {
1183 struct btrfs_root *root;
1184 int ret;
1185
1186 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1187 return fs_info->tree_root;
1188 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1189 return fs_info->extent_root;
1190 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1191 return fs_info->chunk_root;
1192 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1193 return fs_info->dev_root;
1194 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1195 return fs_info->csum_root;
1196 again:
1197 spin_lock(&fs_info->fs_roots_radix_lock);
1198 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1199 (unsigned long)location->objectid);
1200 spin_unlock(&fs_info->fs_roots_radix_lock);
1201 if (root)
1202 return root;
1203
1204 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1205 if (IS_ERR(root))
1206 return root;
1207
1208 set_anon_super(&root->anon_super, NULL);
1209
1210 if (btrfs_root_refs(&root->root_item) == 0) {
1211 ret = -ENOENT;
1212 goto fail;
1213 }
1214
1215 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1216 if (ret < 0)
1217 goto fail;
1218 if (ret == 0)
1219 root->orphan_item_inserted = 1;
1220
1221 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1222 if (ret)
1223 goto fail;
1224
1225 spin_lock(&fs_info->fs_roots_radix_lock);
1226 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1227 (unsigned long)root->root_key.objectid,
1228 root);
1229 if (ret == 0)
1230 root->in_radix = 1;
1231
1232 spin_unlock(&fs_info->fs_roots_radix_lock);
1233 radix_tree_preload_end();
1234 if (ret) {
1235 if (ret == -EEXIST) {
1236 free_fs_root(root);
1237 goto again;
1238 }
1239 goto fail;
1240 }
1241
1242 ret = btrfs_find_dead_roots(fs_info->tree_root,
1243 root->root_key.objectid);
1244 WARN_ON(ret);
1245 return root;
1246 fail:
1247 free_fs_root(root);
1248 return ERR_PTR(ret);
1249 }
1250
1251 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1252 struct btrfs_key *location,
1253 const char *name, int namelen)
1254 {
1255 return btrfs_read_fs_root_no_name(fs_info, location);
1256 #if 0
1257 struct btrfs_root *root;
1258 int ret;
1259
1260 root = btrfs_read_fs_root_no_name(fs_info, location);
1261 if (!root)
1262 return NULL;
1263
1264 if (root->in_sysfs)
1265 return root;
1266
1267 ret = btrfs_set_root_name(root, name, namelen);
1268 if (ret) {
1269 free_extent_buffer(root->node);
1270 kfree(root);
1271 return ERR_PTR(ret);
1272 }
1273
1274 ret = btrfs_sysfs_add_root(root);
1275 if (ret) {
1276 free_extent_buffer(root->node);
1277 kfree(root->name);
1278 kfree(root);
1279 return ERR_PTR(ret);
1280 }
1281 root->in_sysfs = 1;
1282 return root;
1283 #endif
1284 }
1285
1286 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1287 {
1288 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1289 int ret = 0;
1290 struct btrfs_device *device;
1291 struct backing_dev_info *bdi;
1292
1293 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1294 if (!device->bdev)
1295 continue;
1296 bdi = blk_get_backing_dev_info(device->bdev);
1297 if (bdi && bdi_congested(bdi, bdi_bits)) {
1298 ret = 1;
1299 break;
1300 }
1301 }
1302 return ret;
1303 }
1304
1305 /*
1306 * this unplugs every device on the box, and it is only used when page
1307 * is null
1308 */
1309 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1310 {
1311 struct btrfs_device *device;
1312 struct btrfs_fs_info *info;
1313
1314 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1315 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1316 if (!device->bdev)
1317 continue;
1318
1319 bdi = blk_get_backing_dev_info(device->bdev);
1320 if (bdi->unplug_io_fn)
1321 bdi->unplug_io_fn(bdi, page);
1322 }
1323 }
1324
1325 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1326 {
1327 struct inode *inode;
1328 struct extent_map_tree *em_tree;
1329 struct extent_map *em;
1330 struct address_space *mapping;
1331 u64 offset;
1332
1333 /* the generic O_DIRECT read code does this */
1334 if (1 || !page) {
1335 __unplug_io_fn(bdi, page);
1336 return;
1337 }
1338
1339 /*
1340 * page->mapping may change at any time. Get a consistent copy
1341 * and use that for everything below
1342 */
1343 smp_mb();
1344 mapping = page->mapping;
1345 if (!mapping)
1346 return;
1347
1348 inode = mapping->host;
1349
1350 /*
1351 * don't do the expensive searching for a small number of
1352 * devices
1353 */
1354 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1355 __unplug_io_fn(bdi, page);
1356 return;
1357 }
1358
1359 offset = page_offset(page);
1360
1361 em_tree = &BTRFS_I(inode)->extent_tree;
1362 read_lock(&em_tree->lock);
1363 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1364 read_unlock(&em_tree->lock);
1365 if (!em) {
1366 __unplug_io_fn(bdi, page);
1367 return;
1368 }
1369
1370 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1371 free_extent_map(em);
1372 __unplug_io_fn(bdi, page);
1373 return;
1374 }
1375 offset = offset - em->start;
1376 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1377 em->block_start + offset, page);
1378 free_extent_map(em);
1379 }
1380
1381 /*
1382 * If this fails, caller must call bdi_destroy() to get rid of the
1383 * bdi again.
1384 */
1385 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1386 {
1387 int err;
1388
1389 bdi->capabilities = BDI_CAP_MAP_COPY;
1390 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1391 if (err)
1392 return err;
1393
1394 bdi->ra_pages = default_backing_dev_info.ra_pages;
1395 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1396 bdi->unplug_io_data = info;
1397 bdi->congested_fn = btrfs_congested_fn;
1398 bdi->congested_data = info;
1399 return 0;
1400 }
1401
1402 static int bio_ready_for_csum(struct bio *bio)
1403 {
1404 u64 length = 0;
1405 u64 buf_len = 0;
1406 u64 start = 0;
1407 struct page *page;
1408 struct extent_io_tree *io_tree = NULL;
1409 struct bio_vec *bvec;
1410 int i;
1411 int ret;
1412
1413 bio_for_each_segment(bvec, bio, i) {
1414 page = bvec->bv_page;
1415 if (page->private == EXTENT_PAGE_PRIVATE) {
1416 length += bvec->bv_len;
1417 continue;
1418 }
1419 if (!page->private) {
1420 length += bvec->bv_len;
1421 continue;
1422 }
1423 length = bvec->bv_len;
1424 buf_len = page->private >> 2;
1425 start = page_offset(page) + bvec->bv_offset;
1426 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1427 }
1428 /* are we fully contained in this bio? */
1429 if (buf_len <= length)
1430 return 1;
1431
1432 ret = extent_range_uptodate(io_tree, start + length,
1433 start + buf_len - 1);
1434 return ret;
1435 }
1436
1437 /*
1438 * called by the kthread helper functions to finally call the bio end_io
1439 * functions. This is where read checksum verification actually happens
1440 */
1441 static void end_workqueue_fn(struct btrfs_work *work)
1442 {
1443 struct bio *bio;
1444 struct end_io_wq *end_io_wq;
1445 struct btrfs_fs_info *fs_info;
1446 int error;
1447
1448 end_io_wq = container_of(work, struct end_io_wq, work);
1449 bio = end_io_wq->bio;
1450 fs_info = end_io_wq->info;
1451
1452 /* metadata bio reads are special because the whole tree block must
1453 * be checksummed at once. This makes sure the entire block is in
1454 * ram and up to date before trying to verify things. For
1455 * blocksize <= pagesize, it is basically a noop
1456 */
1457 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1458 !bio_ready_for_csum(bio)) {
1459 btrfs_queue_worker(&fs_info->endio_meta_workers,
1460 &end_io_wq->work);
1461 return;
1462 }
1463 error = end_io_wq->error;
1464 bio->bi_private = end_io_wq->private;
1465 bio->bi_end_io = end_io_wq->end_io;
1466 kfree(end_io_wq);
1467 bio_endio(bio, error);
1468 }
1469
1470 static int cleaner_kthread(void *arg)
1471 {
1472 struct btrfs_root *root = arg;
1473
1474 do {
1475 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1476
1477 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1478 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1479 btrfs_run_delayed_iputs(root);
1480 btrfs_clean_old_snapshots(root);
1481 mutex_unlock(&root->fs_info->cleaner_mutex);
1482 }
1483
1484 if (freezing(current)) {
1485 refrigerator();
1486 } else {
1487 set_current_state(TASK_INTERRUPTIBLE);
1488 if (!kthread_should_stop())
1489 schedule();
1490 __set_current_state(TASK_RUNNING);
1491 }
1492 } while (!kthread_should_stop());
1493 return 0;
1494 }
1495
1496 static int transaction_kthread(void *arg)
1497 {
1498 struct btrfs_root *root = arg;
1499 struct btrfs_trans_handle *trans;
1500 struct btrfs_transaction *cur;
1501 u64 transid;
1502 unsigned long now;
1503 unsigned long delay;
1504 int ret;
1505
1506 do {
1507 delay = HZ * 30;
1508 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1509 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1510
1511 spin_lock(&root->fs_info->new_trans_lock);
1512 cur = root->fs_info->running_transaction;
1513 if (!cur) {
1514 spin_unlock(&root->fs_info->new_trans_lock);
1515 goto sleep;
1516 }
1517
1518 now = get_seconds();
1519 if (!cur->blocked &&
1520 (now < cur->start_time || now - cur->start_time < 30)) {
1521 spin_unlock(&root->fs_info->new_trans_lock);
1522 delay = HZ * 5;
1523 goto sleep;
1524 }
1525 transid = cur->transid;
1526 spin_unlock(&root->fs_info->new_trans_lock);
1527
1528 trans = btrfs_join_transaction(root, 1);
1529 if (transid == trans->transid) {
1530 ret = btrfs_commit_transaction(trans, root);
1531 BUG_ON(ret);
1532 } else {
1533 btrfs_end_transaction(trans, root);
1534 }
1535 sleep:
1536 wake_up_process(root->fs_info->cleaner_kthread);
1537 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1538
1539 if (freezing(current)) {
1540 refrigerator();
1541 } else {
1542 set_current_state(TASK_INTERRUPTIBLE);
1543 if (!kthread_should_stop() &&
1544 !btrfs_transaction_blocked(root->fs_info))
1545 schedule_timeout(delay);
1546 __set_current_state(TASK_RUNNING);
1547 }
1548 } while (!kthread_should_stop());
1549 return 0;
1550 }
1551
1552 struct btrfs_root *open_ctree(struct super_block *sb,
1553 struct btrfs_fs_devices *fs_devices,
1554 char *options)
1555 {
1556 u32 sectorsize;
1557 u32 nodesize;
1558 u32 leafsize;
1559 u32 blocksize;
1560 u32 stripesize;
1561 u64 generation;
1562 u64 features;
1563 struct btrfs_key location;
1564 struct buffer_head *bh;
1565 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1566 GFP_NOFS);
1567 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1568 GFP_NOFS);
1569 struct btrfs_root *tree_root = btrfs_sb(sb);
1570 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1571 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1572 GFP_NOFS);
1573 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1574 GFP_NOFS);
1575 struct btrfs_root *log_tree_root;
1576
1577 int ret;
1578 int err = -EINVAL;
1579
1580 struct btrfs_super_block *disk_super;
1581
1582 if (!extent_root || !tree_root || !fs_info ||
1583 !chunk_root || !dev_root || !csum_root) {
1584 err = -ENOMEM;
1585 goto fail;
1586 }
1587
1588 ret = init_srcu_struct(&fs_info->subvol_srcu);
1589 if (ret) {
1590 err = ret;
1591 goto fail;
1592 }
1593
1594 ret = setup_bdi(fs_info, &fs_info->bdi);
1595 if (ret) {
1596 err = ret;
1597 goto fail_srcu;
1598 }
1599
1600 fs_info->btree_inode = new_inode(sb);
1601 if (!fs_info->btree_inode) {
1602 err = -ENOMEM;
1603 goto fail_bdi;
1604 }
1605
1606 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1607 INIT_LIST_HEAD(&fs_info->trans_list);
1608 INIT_LIST_HEAD(&fs_info->dead_roots);
1609 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1610 INIT_LIST_HEAD(&fs_info->hashers);
1611 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1612 INIT_LIST_HEAD(&fs_info->ordered_operations);
1613 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1614 spin_lock_init(&fs_info->delalloc_lock);
1615 spin_lock_init(&fs_info->new_trans_lock);
1616 spin_lock_init(&fs_info->ref_cache_lock);
1617 spin_lock_init(&fs_info->fs_roots_radix_lock);
1618 spin_lock_init(&fs_info->delayed_iput_lock);
1619
1620 init_completion(&fs_info->kobj_unregister);
1621 fs_info->tree_root = tree_root;
1622 fs_info->extent_root = extent_root;
1623 fs_info->csum_root = csum_root;
1624 fs_info->chunk_root = chunk_root;
1625 fs_info->dev_root = dev_root;
1626 fs_info->fs_devices = fs_devices;
1627 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1628 INIT_LIST_HEAD(&fs_info->space_info);
1629 btrfs_mapping_init(&fs_info->mapping_tree);
1630 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1631 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1632 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1633 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1634 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1635 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1636 mutex_init(&fs_info->durable_block_rsv_mutex);
1637 atomic_set(&fs_info->nr_async_submits, 0);
1638 atomic_set(&fs_info->async_delalloc_pages, 0);
1639 atomic_set(&fs_info->async_submit_draining, 0);
1640 atomic_set(&fs_info->nr_async_bios, 0);
1641 fs_info->sb = sb;
1642 fs_info->max_inline = 8192 * 1024;
1643 fs_info->metadata_ratio = 0;
1644
1645 fs_info->thread_pool_size = min_t(unsigned long,
1646 num_online_cpus() + 2, 8);
1647
1648 INIT_LIST_HEAD(&fs_info->ordered_extents);
1649 spin_lock_init(&fs_info->ordered_extent_lock);
1650
1651 sb->s_blocksize = 4096;
1652 sb->s_blocksize_bits = blksize_bits(4096);
1653 sb->s_bdi = &fs_info->bdi;
1654
1655 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1656 fs_info->btree_inode->i_nlink = 1;
1657 /*
1658 * we set the i_size on the btree inode to the max possible int.
1659 * the real end of the address space is determined by all of
1660 * the devices in the system
1661 */
1662 fs_info->btree_inode->i_size = OFFSET_MAX;
1663 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1664 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1665
1666 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1667 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1668 fs_info->btree_inode->i_mapping,
1669 GFP_NOFS);
1670 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1671 GFP_NOFS);
1672
1673 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1674
1675 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1676 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1677 sizeof(struct btrfs_key));
1678 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1679 insert_inode_hash(fs_info->btree_inode);
1680
1681 spin_lock_init(&fs_info->block_group_cache_lock);
1682 fs_info->block_group_cache_tree = RB_ROOT;
1683
1684 extent_io_tree_init(&fs_info->freed_extents[0],
1685 fs_info->btree_inode->i_mapping, GFP_NOFS);
1686 extent_io_tree_init(&fs_info->freed_extents[1],
1687 fs_info->btree_inode->i_mapping, GFP_NOFS);
1688 fs_info->pinned_extents = &fs_info->freed_extents[0];
1689 fs_info->do_barriers = 1;
1690
1691
1692 mutex_init(&fs_info->trans_mutex);
1693 mutex_init(&fs_info->ordered_operations_mutex);
1694 mutex_init(&fs_info->tree_log_mutex);
1695 mutex_init(&fs_info->chunk_mutex);
1696 mutex_init(&fs_info->transaction_kthread_mutex);
1697 mutex_init(&fs_info->cleaner_mutex);
1698 mutex_init(&fs_info->volume_mutex);
1699 init_rwsem(&fs_info->extent_commit_sem);
1700 init_rwsem(&fs_info->cleanup_work_sem);
1701 init_rwsem(&fs_info->subvol_sem);
1702
1703 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1704 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1705
1706 init_waitqueue_head(&fs_info->transaction_throttle);
1707 init_waitqueue_head(&fs_info->transaction_wait);
1708 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1709 init_waitqueue_head(&fs_info->async_submit_wait);
1710
1711 __setup_root(4096, 4096, 4096, 4096, tree_root,
1712 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1713
1714 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1715 if (!bh)
1716 goto fail_iput;
1717
1718 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1719 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1720 sizeof(fs_info->super_for_commit));
1721 brelse(bh);
1722
1723 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1724
1725 disk_super = &fs_info->super_copy;
1726 if (!btrfs_super_root(disk_super))
1727 goto fail_iput;
1728
1729 ret = btrfs_parse_options(tree_root, options);
1730 if (ret) {
1731 err = ret;
1732 goto fail_iput;
1733 }
1734
1735 features = btrfs_super_incompat_flags(disk_super) &
1736 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1737 if (features) {
1738 printk(KERN_ERR "BTRFS: couldn't mount because of "
1739 "unsupported optional features (%Lx).\n",
1740 (unsigned long long)features);
1741 err = -EINVAL;
1742 goto fail_iput;
1743 }
1744
1745 features = btrfs_super_incompat_flags(disk_super);
1746 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1747 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1748 btrfs_set_super_incompat_flags(disk_super, features);
1749 }
1750
1751 features = btrfs_super_compat_ro_flags(disk_super) &
1752 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1753 if (!(sb->s_flags & MS_RDONLY) && features) {
1754 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1755 "unsupported option features (%Lx).\n",
1756 (unsigned long long)features);
1757 err = -EINVAL;
1758 goto fail_iput;
1759 }
1760
1761 btrfs_init_workers(&fs_info->generic_worker,
1762 "genwork", 1, NULL);
1763
1764 btrfs_init_workers(&fs_info->workers, "worker",
1765 fs_info->thread_pool_size,
1766 &fs_info->generic_worker);
1767
1768 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1769 fs_info->thread_pool_size,
1770 &fs_info->generic_worker);
1771
1772 btrfs_init_workers(&fs_info->submit_workers, "submit",
1773 min_t(u64, fs_devices->num_devices,
1774 fs_info->thread_pool_size),
1775 &fs_info->generic_worker);
1776
1777 /* a higher idle thresh on the submit workers makes it much more
1778 * likely that bios will be send down in a sane order to the
1779 * devices
1780 */
1781 fs_info->submit_workers.idle_thresh = 64;
1782
1783 fs_info->workers.idle_thresh = 16;
1784 fs_info->workers.ordered = 1;
1785
1786 fs_info->delalloc_workers.idle_thresh = 2;
1787 fs_info->delalloc_workers.ordered = 1;
1788
1789 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1790 &fs_info->generic_worker);
1791 btrfs_init_workers(&fs_info->endio_workers, "endio",
1792 fs_info->thread_pool_size,
1793 &fs_info->generic_worker);
1794 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1795 fs_info->thread_pool_size,
1796 &fs_info->generic_worker);
1797 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1798 "endio-meta-write", fs_info->thread_pool_size,
1799 &fs_info->generic_worker);
1800 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1801 fs_info->thread_pool_size,
1802 &fs_info->generic_worker);
1803 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1804 1, &fs_info->generic_worker);
1805
1806 /*
1807 * endios are largely parallel and should have a very
1808 * low idle thresh
1809 */
1810 fs_info->endio_workers.idle_thresh = 4;
1811 fs_info->endio_meta_workers.idle_thresh = 4;
1812
1813 fs_info->endio_write_workers.idle_thresh = 2;
1814 fs_info->endio_meta_write_workers.idle_thresh = 2;
1815
1816 btrfs_start_workers(&fs_info->workers, 1);
1817 btrfs_start_workers(&fs_info->generic_worker, 1);
1818 btrfs_start_workers(&fs_info->submit_workers, 1);
1819 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1820 btrfs_start_workers(&fs_info->fixup_workers, 1);
1821 btrfs_start_workers(&fs_info->endio_workers, 1);
1822 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1823 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1824 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1825 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1826
1827 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1828 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1829 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1830
1831 nodesize = btrfs_super_nodesize(disk_super);
1832 leafsize = btrfs_super_leafsize(disk_super);
1833 sectorsize = btrfs_super_sectorsize(disk_super);
1834 stripesize = btrfs_super_stripesize(disk_super);
1835 tree_root->nodesize = nodesize;
1836 tree_root->leafsize = leafsize;
1837 tree_root->sectorsize = sectorsize;
1838 tree_root->stripesize = stripesize;
1839
1840 sb->s_blocksize = sectorsize;
1841 sb->s_blocksize_bits = blksize_bits(sectorsize);
1842
1843 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1844 sizeof(disk_super->magic))) {
1845 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1846 goto fail_sb_buffer;
1847 }
1848
1849 mutex_lock(&fs_info->chunk_mutex);
1850 ret = btrfs_read_sys_array(tree_root);
1851 mutex_unlock(&fs_info->chunk_mutex);
1852 if (ret) {
1853 printk(KERN_WARNING "btrfs: failed to read the system "
1854 "array on %s\n", sb->s_id);
1855 goto fail_sb_buffer;
1856 }
1857
1858 blocksize = btrfs_level_size(tree_root,
1859 btrfs_super_chunk_root_level(disk_super));
1860 generation = btrfs_super_chunk_root_generation(disk_super);
1861
1862 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1863 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1864
1865 chunk_root->node = read_tree_block(chunk_root,
1866 btrfs_super_chunk_root(disk_super),
1867 blocksize, generation);
1868 BUG_ON(!chunk_root->node);
1869 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1870 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1871 sb->s_id);
1872 goto fail_chunk_root;
1873 }
1874 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1875 chunk_root->commit_root = btrfs_root_node(chunk_root);
1876
1877 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1878 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1879 BTRFS_UUID_SIZE);
1880
1881 mutex_lock(&fs_info->chunk_mutex);
1882 ret = btrfs_read_chunk_tree(chunk_root);
1883 mutex_unlock(&fs_info->chunk_mutex);
1884 if (ret) {
1885 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1886 sb->s_id);
1887 goto fail_chunk_root;
1888 }
1889
1890 btrfs_close_extra_devices(fs_devices);
1891
1892 blocksize = btrfs_level_size(tree_root,
1893 btrfs_super_root_level(disk_super));
1894 generation = btrfs_super_generation(disk_super);
1895
1896 tree_root->node = read_tree_block(tree_root,
1897 btrfs_super_root(disk_super),
1898 blocksize, generation);
1899 if (!tree_root->node)
1900 goto fail_chunk_root;
1901 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1902 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1903 sb->s_id);
1904 goto fail_tree_root;
1905 }
1906 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1907 tree_root->commit_root = btrfs_root_node(tree_root);
1908
1909 ret = find_and_setup_root(tree_root, fs_info,
1910 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1911 if (ret)
1912 goto fail_tree_root;
1913 extent_root->track_dirty = 1;
1914
1915 ret = find_and_setup_root(tree_root, fs_info,
1916 BTRFS_DEV_TREE_OBJECTID, dev_root);
1917 if (ret)
1918 goto fail_extent_root;
1919 dev_root->track_dirty = 1;
1920
1921 ret = find_and_setup_root(tree_root, fs_info,
1922 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1923 if (ret)
1924 goto fail_dev_root;
1925
1926 csum_root->track_dirty = 1;
1927
1928 fs_info->generation = generation;
1929 fs_info->last_trans_committed = generation;
1930 fs_info->data_alloc_profile = (u64)-1;
1931 fs_info->metadata_alloc_profile = (u64)-1;
1932 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1933
1934 ret = btrfs_read_block_groups(extent_root);
1935 if (ret) {
1936 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1937 goto fail_block_groups;
1938 }
1939
1940 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1941 "btrfs-cleaner");
1942 if (IS_ERR(fs_info->cleaner_kthread))
1943 goto fail_block_groups;
1944
1945 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1946 tree_root,
1947 "btrfs-transaction");
1948 if (IS_ERR(fs_info->transaction_kthread))
1949 goto fail_cleaner;
1950
1951 if (!btrfs_test_opt(tree_root, SSD) &&
1952 !btrfs_test_opt(tree_root, NOSSD) &&
1953 !fs_info->fs_devices->rotating) {
1954 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1955 "mode\n");
1956 btrfs_set_opt(fs_info->mount_opt, SSD);
1957 }
1958
1959 if (btrfs_super_log_root(disk_super) != 0) {
1960 u64 bytenr = btrfs_super_log_root(disk_super);
1961
1962 if (fs_devices->rw_devices == 0) {
1963 printk(KERN_WARNING "Btrfs log replay required "
1964 "on RO media\n");
1965 err = -EIO;
1966 goto fail_trans_kthread;
1967 }
1968 blocksize =
1969 btrfs_level_size(tree_root,
1970 btrfs_super_log_root_level(disk_super));
1971
1972 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1973 if (!log_tree_root) {
1974 err = -ENOMEM;
1975 goto fail_trans_kthread;
1976 }
1977
1978 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1979 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1980
1981 log_tree_root->node = read_tree_block(tree_root, bytenr,
1982 blocksize,
1983 generation + 1);
1984 ret = btrfs_recover_log_trees(log_tree_root);
1985 BUG_ON(ret);
1986
1987 if (sb->s_flags & MS_RDONLY) {
1988 ret = btrfs_commit_super(tree_root);
1989 BUG_ON(ret);
1990 }
1991 }
1992
1993 ret = btrfs_find_orphan_roots(tree_root);
1994 BUG_ON(ret);
1995
1996 if (!(sb->s_flags & MS_RDONLY)) {
1997 ret = btrfs_cleanup_fs_roots(fs_info);
1998 BUG_ON(ret);
1999
2000 ret = btrfs_recover_relocation(tree_root);
2001 if (ret < 0) {
2002 printk(KERN_WARNING
2003 "btrfs: failed to recover relocation\n");
2004 err = -EINVAL;
2005 goto fail_trans_kthread;
2006 }
2007 }
2008
2009 location.objectid = BTRFS_FS_TREE_OBJECTID;
2010 location.type = BTRFS_ROOT_ITEM_KEY;
2011 location.offset = (u64)-1;
2012
2013 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2014 if (!fs_info->fs_root)
2015 goto fail_trans_kthread;
2016 if (IS_ERR(fs_info->fs_root)) {
2017 err = PTR_ERR(fs_info->fs_root);
2018 goto fail_trans_kthread;
2019 }
2020
2021 if (!(sb->s_flags & MS_RDONLY)) {
2022 down_read(&fs_info->cleanup_work_sem);
2023 btrfs_orphan_cleanup(fs_info->fs_root);
2024 btrfs_orphan_cleanup(fs_info->tree_root);
2025 up_read(&fs_info->cleanup_work_sem);
2026 }
2027
2028 return tree_root;
2029
2030 fail_trans_kthread:
2031 kthread_stop(fs_info->transaction_kthread);
2032 fail_cleaner:
2033 kthread_stop(fs_info->cleaner_kthread);
2034
2035 /*
2036 * make sure we're done with the btree inode before we stop our
2037 * kthreads
2038 */
2039 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2040 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2041
2042 fail_block_groups:
2043 btrfs_free_block_groups(fs_info);
2044 free_extent_buffer(csum_root->node);
2045 free_extent_buffer(csum_root->commit_root);
2046 fail_dev_root:
2047 free_extent_buffer(dev_root->node);
2048 free_extent_buffer(dev_root->commit_root);
2049 fail_extent_root:
2050 free_extent_buffer(extent_root->node);
2051 free_extent_buffer(extent_root->commit_root);
2052 fail_tree_root:
2053 free_extent_buffer(tree_root->node);
2054 free_extent_buffer(tree_root->commit_root);
2055 fail_chunk_root:
2056 free_extent_buffer(chunk_root->node);
2057 free_extent_buffer(chunk_root->commit_root);
2058 fail_sb_buffer:
2059 btrfs_stop_workers(&fs_info->generic_worker);
2060 btrfs_stop_workers(&fs_info->fixup_workers);
2061 btrfs_stop_workers(&fs_info->delalloc_workers);
2062 btrfs_stop_workers(&fs_info->workers);
2063 btrfs_stop_workers(&fs_info->endio_workers);
2064 btrfs_stop_workers(&fs_info->endio_meta_workers);
2065 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2066 btrfs_stop_workers(&fs_info->endio_write_workers);
2067 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2068 btrfs_stop_workers(&fs_info->submit_workers);
2069 fail_iput:
2070 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2071 iput(fs_info->btree_inode);
2072
2073 btrfs_close_devices(fs_info->fs_devices);
2074 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2075 fail_bdi:
2076 bdi_destroy(&fs_info->bdi);
2077 fail_srcu:
2078 cleanup_srcu_struct(&fs_info->subvol_srcu);
2079 fail:
2080 kfree(extent_root);
2081 kfree(tree_root);
2082 kfree(fs_info);
2083 kfree(chunk_root);
2084 kfree(dev_root);
2085 kfree(csum_root);
2086 return ERR_PTR(err);
2087 }
2088
2089 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2090 {
2091 char b[BDEVNAME_SIZE];
2092
2093 if (uptodate) {
2094 set_buffer_uptodate(bh);
2095 } else {
2096 if (printk_ratelimit()) {
2097 printk(KERN_WARNING "lost page write due to "
2098 "I/O error on %s\n",
2099 bdevname(bh->b_bdev, b));
2100 }
2101 /* note, we dont' set_buffer_write_io_error because we have
2102 * our own ways of dealing with the IO errors
2103 */
2104 clear_buffer_uptodate(bh);
2105 }
2106 unlock_buffer(bh);
2107 put_bh(bh);
2108 }
2109
2110 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2111 {
2112 struct buffer_head *bh;
2113 struct buffer_head *latest = NULL;
2114 struct btrfs_super_block *super;
2115 int i;
2116 u64 transid = 0;
2117 u64 bytenr;
2118
2119 /* we would like to check all the supers, but that would make
2120 * a btrfs mount succeed after a mkfs from a different FS.
2121 * So, we need to add a special mount option to scan for
2122 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2123 */
2124 for (i = 0; i < 1; i++) {
2125 bytenr = btrfs_sb_offset(i);
2126 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2127 break;
2128 bh = __bread(bdev, bytenr / 4096, 4096);
2129 if (!bh)
2130 continue;
2131
2132 super = (struct btrfs_super_block *)bh->b_data;
2133 if (btrfs_super_bytenr(super) != bytenr ||
2134 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2135 sizeof(super->magic))) {
2136 brelse(bh);
2137 continue;
2138 }
2139
2140 if (!latest || btrfs_super_generation(super) > transid) {
2141 brelse(latest);
2142 latest = bh;
2143 transid = btrfs_super_generation(super);
2144 } else {
2145 brelse(bh);
2146 }
2147 }
2148 return latest;
2149 }
2150
2151 /*
2152 * this should be called twice, once with wait == 0 and
2153 * once with wait == 1. When wait == 0 is done, all the buffer heads
2154 * we write are pinned.
2155 *
2156 * They are released when wait == 1 is done.
2157 * max_mirrors must be the same for both runs, and it indicates how
2158 * many supers on this one device should be written.
2159 *
2160 * max_mirrors == 0 means to write them all.
2161 */
2162 static int write_dev_supers(struct btrfs_device *device,
2163 struct btrfs_super_block *sb,
2164 int do_barriers, int wait, int max_mirrors)
2165 {
2166 struct buffer_head *bh;
2167 int i;
2168 int ret;
2169 int errors = 0;
2170 u32 crc;
2171 u64 bytenr;
2172 int last_barrier = 0;
2173
2174 if (max_mirrors == 0)
2175 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2176
2177 /* make sure only the last submit_bh does a barrier */
2178 if (do_barriers) {
2179 for (i = 0; i < max_mirrors; i++) {
2180 bytenr = btrfs_sb_offset(i);
2181 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2182 device->total_bytes)
2183 break;
2184 last_barrier = i;
2185 }
2186 }
2187
2188 for (i = 0; i < max_mirrors; i++) {
2189 bytenr = btrfs_sb_offset(i);
2190 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2191 break;
2192
2193 if (wait) {
2194 bh = __find_get_block(device->bdev, bytenr / 4096,
2195 BTRFS_SUPER_INFO_SIZE);
2196 BUG_ON(!bh);
2197 wait_on_buffer(bh);
2198 if (!buffer_uptodate(bh))
2199 errors++;
2200
2201 /* drop our reference */
2202 brelse(bh);
2203
2204 /* drop the reference from the wait == 0 run */
2205 brelse(bh);
2206 continue;
2207 } else {
2208 btrfs_set_super_bytenr(sb, bytenr);
2209
2210 crc = ~(u32)0;
2211 crc = btrfs_csum_data(NULL, (char *)sb +
2212 BTRFS_CSUM_SIZE, crc,
2213 BTRFS_SUPER_INFO_SIZE -
2214 BTRFS_CSUM_SIZE);
2215 btrfs_csum_final(crc, sb->csum);
2216
2217 /*
2218 * one reference for us, and we leave it for the
2219 * caller
2220 */
2221 bh = __getblk(device->bdev, bytenr / 4096,
2222 BTRFS_SUPER_INFO_SIZE);
2223 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2224
2225 /* one reference for submit_bh */
2226 get_bh(bh);
2227
2228 set_buffer_uptodate(bh);
2229 lock_buffer(bh);
2230 bh->b_end_io = btrfs_end_buffer_write_sync;
2231 }
2232
2233 if (i == last_barrier && do_barriers)
2234 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2235 else
2236 ret = submit_bh(WRITE_SYNC, bh);
2237
2238 if (ret)
2239 errors++;
2240 }
2241 return errors < i ? 0 : -1;
2242 }
2243
2244 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2245 {
2246 struct list_head *head;
2247 struct btrfs_device *dev;
2248 struct btrfs_super_block *sb;
2249 struct btrfs_dev_item *dev_item;
2250 int ret;
2251 int do_barriers;
2252 int max_errors;
2253 int total_errors = 0;
2254 u64 flags;
2255
2256 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2257 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2258
2259 sb = &root->fs_info->super_for_commit;
2260 dev_item = &sb->dev_item;
2261
2262 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2263 head = &root->fs_info->fs_devices->devices;
2264 list_for_each_entry(dev, head, dev_list) {
2265 if (!dev->bdev) {
2266 total_errors++;
2267 continue;
2268 }
2269 if (!dev->in_fs_metadata || !dev->writeable)
2270 continue;
2271
2272 btrfs_set_stack_device_generation(dev_item, 0);
2273 btrfs_set_stack_device_type(dev_item, dev->type);
2274 btrfs_set_stack_device_id(dev_item, dev->devid);
2275 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2276 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2277 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2278 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2279 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2280 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2281 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2282
2283 flags = btrfs_super_flags(sb);
2284 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2285
2286 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2287 if (ret)
2288 total_errors++;
2289 }
2290 if (total_errors > max_errors) {
2291 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2292 total_errors);
2293 BUG();
2294 }
2295
2296 total_errors = 0;
2297 list_for_each_entry(dev, head, dev_list) {
2298 if (!dev->bdev)
2299 continue;
2300 if (!dev->in_fs_metadata || !dev->writeable)
2301 continue;
2302
2303 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2304 if (ret)
2305 total_errors++;
2306 }
2307 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2308 if (total_errors > max_errors) {
2309 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2310 total_errors);
2311 BUG();
2312 }
2313 return 0;
2314 }
2315
2316 int write_ctree_super(struct btrfs_trans_handle *trans,
2317 struct btrfs_root *root, int max_mirrors)
2318 {
2319 int ret;
2320
2321 ret = write_all_supers(root, max_mirrors);
2322 return ret;
2323 }
2324
2325 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2326 {
2327 spin_lock(&fs_info->fs_roots_radix_lock);
2328 radix_tree_delete(&fs_info->fs_roots_radix,
2329 (unsigned long)root->root_key.objectid);
2330 spin_unlock(&fs_info->fs_roots_radix_lock);
2331
2332 if (btrfs_root_refs(&root->root_item) == 0)
2333 synchronize_srcu(&fs_info->subvol_srcu);
2334
2335 free_fs_root(root);
2336 return 0;
2337 }
2338
2339 static void free_fs_root(struct btrfs_root *root)
2340 {
2341 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2342 if (root->anon_super.s_dev) {
2343 down_write(&root->anon_super.s_umount);
2344 kill_anon_super(&root->anon_super);
2345 }
2346 free_extent_buffer(root->node);
2347 free_extent_buffer(root->commit_root);
2348 kfree(root->name);
2349 kfree(root);
2350 }
2351
2352 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2353 {
2354 int ret;
2355 struct btrfs_root *gang[8];
2356 int i;
2357
2358 while (!list_empty(&fs_info->dead_roots)) {
2359 gang[0] = list_entry(fs_info->dead_roots.next,
2360 struct btrfs_root, root_list);
2361 list_del(&gang[0]->root_list);
2362
2363 if (gang[0]->in_radix) {
2364 btrfs_free_fs_root(fs_info, gang[0]);
2365 } else {
2366 free_extent_buffer(gang[0]->node);
2367 free_extent_buffer(gang[0]->commit_root);
2368 kfree(gang[0]);
2369 }
2370 }
2371
2372 while (1) {
2373 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2374 (void **)gang, 0,
2375 ARRAY_SIZE(gang));
2376 if (!ret)
2377 break;
2378 for (i = 0; i < ret; i++)
2379 btrfs_free_fs_root(fs_info, gang[i]);
2380 }
2381 return 0;
2382 }
2383
2384 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2385 {
2386 u64 root_objectid = 0;
2387 struct btrfs_root *gang[8];
2388 int i;
2389 int ret;
2390
2391 while (1) {
2392 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2393 (void **)gang, root_objectid,
2394 ARRAY_SIZE(gang));
2395 if (!ret)
2396 break;
2397
2398 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2399 for (i = 0; i < ret; i++) {
2400 root_objectid = gang[i]->root_key.objectid;
2401 btrfs_orphan_cleanup(gang[i]);
2402 }
2403 root_objectid++;
2404 }
2405 return 0;
2406 }
2407
2408 int btrfs_commit_super(struct btrfs_root *root)
2409 {
2410 struct btrfs_trans_handle *trans;
2411 int ret;
2412
2413 mutex_lock(&root->fs_info->cleaner_mutex);
2414 btrfs_run_delayed_iputs(root);
2415 btrfs_clean_old_snapshots(root);
2416 mutex_unlock(&root->fs_info->cleaner_mutex);
2417
2418 /* wait until ongoing cleanup work done */
2419 down_write(&root->fs_info->cleanup_work_sem);
2420 up_write(&root->fs_info->cleanup_work_sem);
2421
2422 trans = btrfs_join_transaction(root, 1);
2423 ret = btrfs_commit_transaction(trans, root);
2424 BUG_ON(ret);
2425 /* run commit again to drop the original snapshot */
2426 trans = btrfs_join_transaction(root, 1);
2427 btrfs_commit_transaction(trans, root);
2428 ret = btrfs_write_and_wait_transaction(NULL, root);
2429 BUG_ON(ret);
2430
2431 ret = write_ctree_super(NULL, root, 0);
2432 return ret;
2433 }
2434
2435 int close_ctree(struct btrfs_root *root)
2436 {
2437 struct btrfs_fs_info *fs_info = root->fs_info;
2438 int ret;
2439
2440 fs_info->closing = 1;
2441 smp_mb();
2442
2443 btrfs_put_block_group_cache(fs_info);
2444 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2445 ret = btrfs_commit_super(root);
2446 if (ret)
2447 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2448 }
2449
2450 kthread_stop(root->fs_info->transaction_kthread);
2451 kthread_stop(root->fs_info->cleaner_kthread);
2452
2453 fs_info->closing = 2;
2454 smp_mb();
2455
2456 if (fs_info->delalloc_bytes) {
2457 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2458 (unsigned long long)fs_info->delalloc_bytes);
2459 }
2460 if (fs_info->total_ref_cache_size) {
2461 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2462 (unsigned long long)fs_info->total_ref_cache_size);
2463 }
2464
2465 free_extent_buffer(fs_info->extent_root->node);
2466 free_extent_buffer(fs_info->extent_root->commit_root);
2467 free_extent_buffer(fs_info->tree_root->node);
2468 free_extent_buffer(fs_info->tree_root->commit_root);
2469 free_extent_buffer(root->fs_info->chunk_root->node);
2470 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2471 free_extent_buffer(root->fs_info->dev_root->node);
2472 free_extent_buffer(root->fs_info->dev_root->commit_root);
2473 free_extent_buffer(root->fs_info->csum_root->node);
2474 free_extent_buffer(root->fs_info->csum_root->commit_root);
2475
2476 btrfs_free_block_groups(root->fs_info);
2477
2478 del_fs_roots(fs_info);
2479
2480 iput(fs_info->btree_inode);
2481
2482 btrfs_stop_workers(&fs_info->generic_worker);
2483 btrfs_stop_workers(&fs_info->fixup_workers);
2484 btrfs_stop_workers(&fs_info->delalloc_workers);
2485 btrfs_stop_workers(&fs_info->workers);
2486 btrfs_stop_workers(&fs_info->endio_workers);
2487 btrfs_stop_workers(&fs_info->endio_meta_workers);
2488 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2489 btrfs_stop_workers(&fs_info->endio_write_workers);
2490 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2491 btrfs_stop_workers(&fs_info->submit_workers);
2492
2493 btrfs_close_devices(fs_info->fs_devices);
2494 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2495
2496 bdi_destroy(&fs_info->bdi);
2497 cleanup_srcu_struct(&fs_info->subvol_srcu);
2498
2499 kfree(fs_info->extent_root);
2500 kfree(fs_info->tree_root);
2501 kfree(fs_info->chunk_root);
2502 kfree(fs_info->dev_root);
2503 kfree(fs_info->csum_root);
2504 return 0;
2505 }
2506
2507 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2508 {
2509 int ret;
2510 struct inode *btree_inode = buf->first_page->mapping->host;
2511
2512 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2513 NULL);
2514 if (!ret)
2515 return ret;
2516
2517 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2518 parent_transid);
2519 return !ret;
2520 }
2521
2522 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2523 {
2524 struct inode *btree_inode = buf->first_page->mapping->host;
2525 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2526 buf);
2527 }
2528
2529 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2530 {
2531 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2532 u64 transid = btrfs_header_generation(buf);
2533 struct inode *btree_inode = root->fs_info->btree_inode;
2534 int was_dirty;
2535
2536 btrfs_assert_tree_locked(buf);
2537 if (transid != root->fs_info->generation) {
2538 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2539 "found %llu running %llu\n",
2540 (unsigned long long)buf->start,
2541 (unsigned long long)transid,
2542 (unsigned long long)root->fs_info->generation);
2543 WARN_ON(1);
2544 }
2545 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2546 buf);
2547 if (!was_dirty) {
2548 spin_lock(&root->fs_info->delalloc_lock);
2549 root->fs_info->dirty_metadata_bytes += buf->len;
2550 spin_unlock(&root->fs_info->delalloc_lock);
2551 }
2552 }
2553
2554 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2555 {
2556 /*
2557 * looks as though older kernels can get into trouble with
2558 * this code, they end up stuck in balance_dirty_pages forever
2559 */
2560 u64 num_dirty;
2561 unsigned long thresh = 32 * 1024 * 1024;
2562
2563 if (current->flags & PF_MEMALLOC)
2564 return;
2565
2566 num_dirty = root->fs_info->dirty_metadata_bytes;
2567
2568 if (num_dirty > thresh) {
2569 balance_dirty_pages_ratelimited_nr(
2570 root->fs_info->btree_inode->i_mapping, 1);
2571 }
2572 return;
2573 }
2574
2575 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2576 {
2577 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2578 int ret;
2579 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2580 if (ret == 0)
2581 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2582 return ret;
2583 }
2584
2585 int btree_lock_page_hook(struct page *page)
2586 {
2587 struct inode *inode = page->mapping->host;
2588 struct btrfs_root *root = BTRFS_I(inode)->root;
2589 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2590 struct extent_buffer *eb;
2591 unsigned long len;
2592 u64 bytenr = page_offset(page);
2593
2594 if (page->private == EXTENT_PAGE_PRIVATE)
2595 goto out;
2596
2597 len = page->private >> 2;
2598 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2599 if (!eb)
2600 goto out;
2601
2602 btrfs_tree_lock(eb);
2603 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2604
2605 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2606 spin_lock(&root->fs_info->delalloc_lock);
2607 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2608 root->fs_info->dirty_metadata_bytes -= eb->len;
2609 else
2610 WARN_ON(1);
2611 spin_unlock(&root->fs_info->delalloc_lock);
2612 }
2613
2614 btrfs_tree_unlock(eb);
2615 free_extent_buffer(eb);
2616 out:
2617 lock_page(page);
2618 return 0;
2619 }
2620
2621 static struct extent_io_ops btree_extent_io_ops = {
2622 .write_cache_pages_lock_hook = btree_lock_page_hook,
2623 .readpage_end_io_hook = btree_readpage_end_io_hook,
2624 .submit_bio_hook = btree_submit_bio_hook,
2625 /* note we're sharing with inode.c for the merge bio hook */
2626 .merge_bio_hook = btrfs_merge_bio_hook,
2627 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree